Method and apparatus for analyzing



R. MESTAS March 19, 1946.

METHOD AND APPARATUS FOR ANALYZING MOTION OR OTHER PHENOMENA Filed Feb. 3, 1941 3 Sheets-Sheet l March 19, 11946., R MESTAS 2,397,032

METHODAND APPARATUS FOR ANALYZING MOTION OR OTHER PHENOMENA Filed Feb. 3, 1941 3 Sheets-Sheet 2 Fig. c?. Figli VOLT/4 G5 arr@ lg, A945. R MESTAS 2,397,032

METHOD AND APPARATUS FOR ANALYZING MOTION OR OTHER PHENOMENA Filed Feb. 3, 1941 5 Sheets-Sheet 5 vais-v V HA PIP/5, Mac/1, F05 r@ HA APR/J Patented Mar. 19, 1946 'Y METHOD AND APPARATUS FOR ANALYZING MOTION OR OTHER PHENOMENA Ricardo Mestas, Los Angeles, Calif., assigner, by mesne assignments, to Kobe, Inc., Huntington Park, Calif., a corporation of California Application February 3, 1941, Serial No. 377,168

6 Claims.

My invention relates to the measurement, indication, or analysis of motion or other phenomena and, more particularly, to a novel method and apparatus capable of wide use in determining operating conditions in a mechanism which may be, in whole or in part, in an inaccessible position.

Generally stated, it is an object of the present invention to provide a novel system for indicating, measuring, or analyzing a plurality of dynamic phenomena, by which I have reference to such variables as the motion of an element, a change in physical properties (e. g., a change in pressure or temperature), a change in direction or speed, acceleration of an element or a change in such acceleration, a change in time, etc,

It is another object of the invention to provide a novel method and apparatus whereby an indicating means can be made responsive successively to diierent dynamic phenomena.

It is also an object of the invention to provide an indicating means movable in a given direction and at right angles with respect thereto, together with means for translating two dynamic phenomena lnixi corresponding electric changes which are simultaneously applied to the indicating means to give an indication thereon oi the manner in which one variable changes with respect to the other. For example, the device can be used to indicate the position of an element with respect to pressure, the position of an element with respect to time, etc.

It is another object of the invention to provide a single indicating means in a system permitting successive application thereto or electric variations corresponding to different dynamic phenomena.

In the preferred embodiment of the invention, the indicating means may comprise an electronic beam directed toward a receptive surface and deectible horizontally and vertically by electromagnetic or electrostatic means. If the hori zontal sweep is made responsive to one dynamic phenomenon and the vertical sweep with respect to the other, the spot or point of impingement of the beam on the receptive surface will sweep.

out a curve. It is an object of the present invention to use such a device in the determination, measurement, or analysis of motion or other dynamic phenomena.

The invention will be described particularly with reference to the determination and analysis of the operation or a piece of equipment, particularly a pump. This pump may provide, for example, a valve mechanism and a piston, and the invention contemplates a system whereby the relative -positions thereof at different times can be determined and the motion of one or both can be analyzed for the purpose of checking timing, resonance, phase relationships, transient phenomena, etc. The invention is also applicable to the determination and analysis of other variables of such a mechanism, such as pressure, temperature, etc., and can be made to show these with respect to time, with respect to some other variable, with respect to other temperatures, pressures, etc., or with respect to other existing conditions to the end that the operation of the mechanism can be accurately analyzed.

The invention also contemplates the successive measurement of different variables in a mechanism in such manner as to produce successive curves which serve to show graphically various variables in the mechanism being tested.

Another object of the invention is to provide an indicating means which moves in one direction repeatedly in response to the passage of time, and which moves in another direction in response to different variables.

Another object of the invention is to provide a system including an indicating means responsive to electric variations, together with means for applying these electric variations selectively to the indicating means to move same in different directions. By way of example, the motion of an element can be changed into corresponding electric variations and these can be applied selectively to the horizontal sweep circuit or the vertical sweep circuit of a cathode ray tube.

It should be clear that the illustration of the invention with reference to the analysis of the operating elements and conditions in a pump is only exemplary, this showing being selected as illustrative of the wide application of the invention. The same principles are applicable to the analysis of other machines and the device is particularly adapted to the indication or determination or analysis of conditions which change relatively slowiy rather than to ultra-high-speed variations taking place in an interval of 116 of a second or less, though it can be adapted to such use. For example, the device can measure conditions in a reciprocating mechanism where the reciprocative cycle is completed in a period of time ranging from a fraction of a second to several mlnutes, yet it will be responsive during the reciprocative period to extremely fast transient variations superimposed on the main motion.

The present application is a continuation-inpart of my applications, Serial Nos. 350,939 and 2 asomar 350,940, filed August 3, 1940, to which reference will be made regarding some of the details of the system, as well as different circuits which can be used in the present invention, if desired.

Referring to the drawings, in which the invention is shown in connection with the problem of analyzing motion in a fluid-operated deep well pump:

Figure 1 is a view, partially in cross section, showing the operating mechanism of such a pump, this figure serving as a utility view showing the modey of connection of the analyzer of the invention;

Figures 2 and 2a show, in vertical section, a. portion of the analyzer, Figure 2 representing the lower portion andFigure 2a the upper portion, the break being indicated by the lines A-A;

Figures 3, 4, and 5 are horizontal cross-sectional views taken respectively as indicated by the lines 3--3, 4 4, and 5--5 of Figures 2 and 2a;

Figure 6 is a sectional view of the electric pressure gauge used in the invention;

Figure '1 is a sectional view, taken generally as indicated by the line I--1 of Figure 6;

Figure 8 is a graphical representation of the manner of compensating for non-linearity or non-proportionality in the system; and

Figure 9 is a general wiring diagram of the system.

Referring particularly to Figure l, the invention is shown as applied to the analysis of conditions in a fluid-operated deep well pump, indicated generally by the numeral I0. The operating details of such a pump are known in the art and will not be herein-described in detail except insofar as is necessary to the understanding of the present invention. Such pumps are the subject of numerous patents to which reference is made for additional details, for example, the patent to Clarence J. Coberly, No, 2,081,223.

Essentially, this type of pump may be of the double-acting type and is shown as including a fluid-actuated motor II comprising a motor piston I2 reciprocable in a cylinder I3 and operatively connected to a pump I4. This pump includes a pump piston I5 reciprocable in a pump cylinder I6 and interconnected with the motor piston I2 by means shown diagrammatically as a rod I1 extending considerably above the piston I2 and considerably below the piston I5.

The fluid-actuated motor II is driven by a stream of high pressure oil delivered through a pipe I8 and the flow thereof to the motor cylinder I3 is controlled by a valve 20 to cause reciprocation of the pistons I2 and I5. lThe valve 20 is usually in the form of a sleeve and may be actuated by fluid pressure, by means not shown, when the piston I2 is at its extreme upper and lower positions. This valve is in the nature of a slide valve and is shown in its upper position, in which it permits high pressure lluid from the pipe I8 to ow inward through a port 2I downward around the rod I1 into a chamber 22, thence through a port 23 to the lower end of the cylinder I3 through a passage 24. This forces the piston upward and the liquid above the piston is displaced through a passage 25, a valve pocket 26, and a port 21 to the annular space provided between the pump and a tubing 28.

When the piston I2 reaches its maximum desired upper position, the valve 20 is moved hydraulically downward by means not shown, thus .permitting a valve pocket 29 to interconnect the pipe I8 and the passage 25 to deliver high pressure uid to the top of the piston I2. Fluid below this piston is displaced upward through the passage 24, then inward and upward through the valvepocket 2B, which is still in communication with the port 21 to permit discharge into the annular space.

As the motor piston I2 reciprocates vertically, the pump piston I5 moves correspondingly, and, by the passages and valves shown, a double-acting pumping action is obtained, the oil from the well being drawn into the structure through a passage 32 and discharged outward through balltype exhaust valves into the annular passage between the pump and the tubing 28 to mingle with the motor-actuating oil.

The invention includes means which can be made responsive to fluid pressure in various portions of the equipment. For purpose of illustration, an electric pressure gauge 35 is shown as responsive to pump pressure within the cylinder I6 and an electric pressure gauge 36 is shown as responsive to motor pressure within the cylinder I3, both pressures being on the up-side of the corresponding pistons. These electric pressure gauges are shown as positioned outside the tubing 28, though they may be positioned within an annular space between the main body of the pump and the tubing 28, if desired, or at any other convenient position, as they serve to translate pressure variations into corresponding electric variations which are transmitted to the surface of the ground through electric connections not shown in Figure 1.

These electric pressure gauges are of novel construction and are o'f a construction best shown in Figures 6 and '1. Referring thereto, the main pump body is shown as providing an orifice 38 in alignment with an opening 39 formed through the tubing' 28. A sleeve 40 is welded to this tubing and is internally threaded to receive a plug 4 I, including a forward-extending tube providing a tapered portion 42, fitting into the orice 38 in fluid-tight relationship. The rear end of the plug 4I is likewise threaded to receive a cap 43. Disposed between the cap 43 and the sleeve 40 is a block 45, there being packing rings 46 concentric with the plug 4I, which are compressed against the block 45 when the cap 43 is tightened. Fluid pressure is transmitted through the plug 4I through a passage 41 and side passages 48 to an annular chamber 49 provided by the block 45.

This block is rigidly mounted in a housing 5i] and retains the lower end of a Bourdon tube 5I which is closed at its upper end and which communicates at its lower end with the annular chamber 49. This tube is curved in the usual manner, whereby/:increase in internal pressure will tend to straighten the tube.

The upper end of the Bourdon tube 5I carries a block 52, to which is connected an armature 53 which, as viewed in Figure 6, moves laterally in response to pressure variations. The armature 53 is a part of a magnetic circuit including an E-shapecl core 55 rigidly secured to the housing 50 and including end legs 56 and 51 and a shorter central leg 58, respectively surrounded by windings 59, 50, and 6|. The core .and the armature are formed of magnetic material. They may be suitably laminated or formed of a suitable solid material, or of powdered magnetic material bound together by non-magnetic dielectric material, as is known in the art. The armature 53 is disposed between the legs 56 and 51 to provide air gaps 62 and 63. this armature being spaced from the central leg 58 to provide an air gap 64 of constant size so that its reluctance remains constant.

The winding 6i is energized from a suitable alternating or pulsating source, as will be hereinafter described. and establishes two iiux paths, one through the right-hand hall' of the E-shaped core and including the leg 61, the gap 63, and the gap 6l, and another through the left-hand half of the E-shaped core and including the leg B, the gap 62, and the gap 64. As the armature 53 moves slightly leftward in response to an increased pressure, the reluctance of the latter magnetic path will decrease and the reluctance of the former magnetic path will correspondingly increase, the change in reluctance being due to the change in relative size of the gaps 62 and 63. correspondingly, the potential induced in the winding 59 will increase and that induced in the winding 60 will decrease. This change in relative potentials can be transmitted to an indicating means at a remote point, as will be hereinafter described, to move the indicating means in response to changes in pressure.

The armature 53 comprises, in effect, a mechanical element, the motion of which is changed in response to changes in pressure. Pressure changes can thus be made to set up corresponding electric changes which are transmitted to a remote point at which the indicating means is positioned and, as will be hereinafter described, these can be amplified or modified. It will be clear that means other than a Bourdon tube can be used to move the armature 53 in response to other dynamic phenomena, such, for example, as by using a thermo-responsive element adapted to move the armature instead of the Bourdon tube shown.

The invention is shown as including a motion analyzer 1li, shown generally in Figure l and illustrated in detail in Figures 2 and 2a, serving to translate the motion of various mechanical elements into corresponding electric changes which can be transmitted to the indicating means. By way of example, in analyzing the motion of the pump ill, it is often desirable to determine the actual position or change in position of the valve 2li. In accomplishing this, the upper end of the valve threadedly receives a tapered sleeve 12 formed of magnetic material and shown in Figure 2 as in its extreme upper position, in which it abuts against a stop ring 13 retained in a casing 'it extending upward from the top of the main pump body.

As best shown in Figure 3, this tapered sleeve reciprocates with reference to a stator 'l5 and cooperates therewth in defining a magnetic circuit, the reluctance of which changes as the tapered sleeve l2 moves. This stator preferably comprises a multi-pole laminated core built up from punchings or made of suitable solid material, or of powdered magnetic material held together by a binder of non-magnetic dielectric material. It includesV essentially a peripheral ring with a plurality of poles 1B extending inward to denne a circular space in which the tapered sleeve 'l2 reciprocates. Pole pieces or shoes may be provided on the inner ends of these poles, if desired, though this is not essential.

A winding 11 is wound around the poles, the manner of mounting being such that alternate poles are of the same polarity so that adjacent poles are of opposite polarity. This winding may be directly or inductlvely energized from a suitable source of alternating or pulsating potential, and the magnetic circuit is so designed that the flux densities are relatively low so as not to reach the point of saturation.

The tiux path is from one pole. across the air gap, through the tapered sleeve 12, through an adjacent air gap, and thence an adjacent pole, returning to the first pole through the peripheral portion of the stator 15. Each of the air gaps is shown exaggerated in Figure 3, as is also the taper of the sleeve 12 shown in Figure 2. In practice, a taper of only a few thousandths of an inch per inch of length is sufllcient. It is desirable to have a plurality of poles 1B completely surrounding the tapered sleeve so that minor changes in lateral position of the tapered sleeve 12 with respect to the circular opening provided by the poles will not destroy the accuracy of the indication.

It will be clear that the distance across the gaps will change in response to vertical movement of the tapered sleeve 12. This changes 'the reluctance of the magnetic path and, correspondingly, the impedance of the winding 11. Correspondingly, the potential across the winding 11, if inductively energized, or the impedance thereof, if directly energized, will set up electric variations corresponding to the motion of the tapered sleeve. In this way. changes in position of this tapered sleeve can be used to set up corresponding electric changes which can be transmitted to the indicating means, either with or without amplification or modiiication, as will be hereinafter described.

It is also desirable to be able to determine, measure, or analyze piston displacement or motion. This is accomplished, as best shown in Figures 2 and 2a, by detachably connecting to the upper end of the rod I1 an extension 19 including a tapered rod 80, the taper of which is shown somewhat exaggerated for purpose of clarity. In practice, the tapered rod is formed with a very small taper (in the neighborhood of one thousandth of an inch per inch of length), and a sheath 8i formed of relatively non-magnetic material is disposed around the resulting tapered rod 8B, preferably by electroplating. I have found it eminently satisfactory to plate on the surface of the tapered rod a relatively thick coating of chromium, after which the external surface is ground to cylindrical form to permit guiding of the extension 19 by a plurality of rings forming a bearing 82 disposed in a head 83 spaced from the ring 13 by a sleeve 84. This bearing means keeps the extension 19 and the tapered rod 80 centered with respect to a stator 85. The chromium is relatively non-magnetic as compared to the magnetic material of which the tapered rod 8d is formed.

The stator 85 surrounds the tapered rod Bil, as best shown in Figures 2 and 4, and is shaped substantially the same as the stator 15 previously described. A winding 86 is disposed thereon and can be directly or indirectly energized from a source of alternating or pulsating current. The action of the tapered rod in modifying the flux paths is similar to that previously described with reference to the tapered sleeve 12. As the pistons l2 and l5 and their associated rod i1 move up and down, this reciprocative movement is translated into corresponding electric changes which can be made use of by suitably connecting the winding 86 to a remote indicating means, as will be hereinafter described.

As best shown in Figure 2a, the extreme upper end of the tapered rod 80 carries an armature 81, which is formed of a cylindrical piece of magnetic material. When the pistons l2 and I5, and correspondingly the tapered rod 80, are in an extreme upperposition, this armature moves into a circular opening provided by poles of a stator 88, which is generally of the same construction as previously described with reference to the stators 'l5 and 85 except that only two poles are shown. The left-hand pole is surrounded by a primary winding 90, while a secondary winding 9| surrounds the right-hand pole. The primary winding is energized by any suitable source of alternating or pulsating current, and the magnetic coupling between the windings 90 and 9| is markedly influenced by the position of the armature 8l. In fact, it is desired that the magnetic coupling be low so long as the armature 81 is below the stator 88, and that it should increase suddenly to produce a synchronizing impulse when the armature enters the central opening of the stator at the uppermost position of the pistons. .At this time, the voltage induced in the secondary winding 9| will suddenly increase and this is used as a part of the synchronizing means of the invention to bring the indicator means to a zero or predetermined position in step with the reciprocations of the pistons,

The extreme upper end of the device is shown closed by an internally-threaded cap 92 holding in place an insulator 93 through which a plurality of terminals 94 extend. These terminals are connected, by wires not shown, to the various windings of the stators 15, 85, and 88, and conductors may extend upward in the well to the electrical equipment, which may be at a remote point. All of the structural details of the device have not been described in detail, but a preferred construction is adequately illustrated in Figures 2 and 2a, this construction permitting ready assembly of the elements and providing for upward passage of conductors to the terminals 94 through various ports or openings inside the casing 14,

for example, those indicated at 95 (in the ringv '|3), 96 and 91 (adjacent the stator 85), and 98 in a plate 99 above the stator 88), these ports or openings also serving as uid passages to take care of the fluid displaced by the reciprocation of the extension 19 and the tapered rod 80.

The indicating means is designated generally by the numeral in Figure 9 and is shown as comprising a cathode ray tube |0| of the type sending an electronic beam toward a receptive surface. It will be clear, however, that other types of indicating means can be used and that the indication need not necessarily be visual, though it is preferred that the indicating means be capable of producing a latent or immediatelyapparent trace or curve showing the relationships between the various dynamic phenomena. However, separate current-responsive or potential-responsive means can be employed for producing separate indications .or traces which can be used later for the plotting of other curves. It is preerred, however, to use an indicating means which is capable of movement in at least two directions,` preferably at right angles to each other. If an electronic beam (e. g., a stream of electrons in a cathode ray tube) forms, in whole or in part, the indicating means, this beam can be deflected by means known in the art to move in any given direction, usually in two directions, one tending to sweep the beam horizontally across the receptive surface and the other tending to move the beam to sweep vertically across the receptive surface. The terms horizontal and vertical are used herein for purpose of clarity but without limitation, for it will be clear that the sweep circuits can be interposed and that the two directions of sweep can be inclined from the horizontal, remaining at substantially right angles to each other, or the angle therebetween can be such that a n relationship does not exist. In Figure 9, the horizontal sweep circuit is shown diagrammatically as including plates |02 and |03, serving to displace the electronic beam horizontally, the vertical sweep circuit being shown as including plates |04 and |05, serving to control the vertical deflection of the beam.

The receptive surface against which the electronic beam impinges may include a iluorescenttype screen |06. forming a part o f the cathode ray tube |0|, in which event the instantaneous position of the electronic beam will appear as a visible spot. Movement of the electronicbeam will produce a trace or curve which, if the screen |06 is of the retentive type, may exist for a period 0f time ranging from a fraction of a second to several minutes. In the embodiment shown, a camera |01 is focused on the screen |06 and contains an appropriate photographic lm or plate capable of recording single or successive images or traces produced on the screen |08. The photographic emulsion comprises a receptive surface, and it should be clear that the electronic beam can be made to impinge directly thereon to produce the trace rather than rendering the trace visible through use of an intervening screen |06. When I speak of an electronic beam directed toward a receptive surface, I have reference to either system or to other systems in which the electronic beam, or other indicating means, is capable of producing on a receptive surface a latent or irnmediately-apparent image which will show the relationships or any of the individual operations or phenomena which the present invention is adapted to indicate or record. Further, it will be clear that the term indicating means is not used in a restrictive sense but includes such means as recording means, as previously suggested. y

In the illustrated embodiment, the function of the synchronizing means, generally stated, is to maintain the indicating means operating synchronously with respect to the reciprocative movement of the pistons. It is desired, in this embodiment, to be able to move the electronic beam horizontally across the screen |86, starting when the pistons are in their extreme upper position and continuing throughout any desired portion or all of a complete cycle. It is desired, likewise, that the spot (formed by the impingement of the electronic beam on the screen |06) should move horizontally in direct proportion to the passage of time (in the use now to be described), or in proportion to some other dynamic phenomena (in other uses to be later described).

If the spot is to move horizontally in response to the passage of time, I prefer t0 employ a time sweep circuit, indicated generally by the numeral Preferably, this circuit is such as to gen- 'The function of the windings 90 and 9| and the armature 81 is, then, to maintain exact synchroresistor, it being known that the charge on suchV a condenser can be made to build up slowly. The potential applied to the plates |02 and |03 is some function of the potential across such a condenser, as will be described. On the other hand, it is known that the potential across such a condenser does not necessarily increase linearly with time. For example, in Figure 8, curve indicates fragmentally and diagrammatically the general relationship between increase in voltage across the condenser (plotted as ordinates) and time (plotted as abscissa). If this potential were applied directly to the horizontal-displacement plates |02 and |03, the spot would not move in direct proportion to time. While the resulting curves could be later corrected or interpreted, I usually find it desirable to modify the potential delivered to the plates |02 and |33 to correct for the non-linearity of the curve This can be done by use of a suitable ortho-amplifier, indicated generally by the numeral ||2 of Figure 9, which is adjustable-to provide va characteristic curve which compensates for the non-linear input to produce an output potential (impressed across the horizontal-deflection plates |02 and |03) which' varies linearly with time and which follows a straight line in a limited range of the characteristic curve of the amplifier (but over the complete operative range supplied to the indicating device employed). This is suggested in Figure 8 by the straight line H4. Correspondingly, the horizontal movement of the spot will be directly proportional to the passage of time, time being considered, in the present specication, as one of the dynamic phenomena to which the indicating means is to be made responsive.

Referring particularly to the time sweep circuit H0, the condenser, to which reference has previously been made, is indicated by the numeral ||5 and is connected in series with a winding ||6 of a relay ||1 between a plate ||8 and a cathode will be a straight line.

tube |26 being adjustable by an auxiliary variable resistor |33 tapped across a portion of the resistor |90. This cathode is connected to the grid |25 through resistors |35 and |36, the latter providing an adjustable arm |31 connected to the conductor |24, whereby a portion thereof can be short-circuited to permit adjustment. The resistor |3| is likewise variable, providing an arm By adjusting the arm |31, the rate at which the voltage across the condenser ||5 builds up can be varied to obtain a periodicity in the neighborhood of the rate of reciprocation of the pistons. The path of current iiow, traced from conductor |29, is through resistors |30, |33, |35, and |36 to the condenser 5, and then through resistors |3| and |32 to the conductor |28. When the voltage across the condenser I5 builds up high enough to Yovercome the bias of the grid |2|, the tube |20 fires, the condenser I5 discharging through the tube and relay coil ||6.

The variable resistor |33 can be then adjusted to vary the grid bias of the tube |26, and the resistor 3| can be adjusted to correlate the charging curve of the condenser ||5 and the output curve of the amplier so that the resulting curve (suggested by the line H4 of Figure 8 and corresponding to the input delivered to the indicating means), plotted with respect to time, Once these arms have been thus adjusted, they can remain without further change during the test or, in fact, until the characteristics of the tube |26 change with age. This straight-line relationship can be 35 checked by various means. For example, an

||9 of an electronic tube |20, which may be an 50 85type Thyratron tube, such a tube being diagrammatically indicated. The tube |20 comprises the time-base tube and the potential on a grid |2| thereof (controlled synchronously with the piston, as hereinafter described) causes the condenser ||5 to discharge periodically through the tube |20 to effect the desired synchronization between the spot and the piston. The firing of the tube |20 and the discharge of the condenser ||5 therethrough send sui-licient current to the winding I6 to momentarily close the normallyopen contacts l|22 and |23 o'f the relay ||1 for a purpose to be described. The voltage across the condenser |'|5 thus slowly builds up and suddenly drops', and these voltage changes are transmitted by a conductor |24 to a grid |25 of a vacuum tube |26 forming a part of the iortho-ampliiler IIZ. This tube may be of the 6SK7 type, connected substantially as shown.

The requisite D. C. potentials'for the circuit 0 are supplied from a suitable power supply, not shown, this voltage being impressed between the B- conductor |28` and the B+ conductor |29. Connected in series therebetween are resistors |30, |3I, and |32, the cathode potential ot the evenly-pulsating potential (e. g., that obtained by constantly rotating an arm around a circular rheostat) can be applied to the vertical sweep circuit of the cathode ray tube during the time that the horizontal sweep circuit is energized by the time sweep circuit to cause the spot to sweep out a plurality of sharp-peaked wave forms. If the horizontal distance between corresponding points on all successive wave forms is the same, then the desired linearity will have been obtained.

Exactsynchronization with respect to the pump being tested is obtained by making the tube |20 re at the end of each stroke of the piston or at the end of selected strokes. In doing this, I prefer to use a control tube |43, the grid and cathode of which are connected across the secondary winding 9| of the synchronizing means in series with a C-battery |44 providing a proper bias so as to overcome the small induced potential in the winding 9| due to the small coupling existing between the windings and 9| when the armature 81 is out of the magnetic circuit. The cathode of the tube |43 is connected by a conductor |50 to the grid |2I of the time-base tube 20. Connected to the plate of the tube |43 is an adjustable arm |53 sliding along a resistor |54 connected between the conductor |28 and a ta of the Vresistor |30.

To the grid |2| of the tube |20 is connected one terminal of a resistor |55 which limits the grid current when the tube |20 res, the other terminal of this resistor |55 being connected to the arm of a by-pass switch |56. This switch provides two contacts, respectively engaged by the arm when thrown to right or left, the right-hand terminal being connected to the common terminals of the voltage-dividing resistors |3| and |32, the left-hand terminal being common to 5 the conductor |29. If the switch |56 is thrown to .the right, the grid bias of the tube |20 is determined by the potential across the nonshorted portion of resistor I3|, delivered through the resistor |55. When the switch |56 is thrownv to the left, this grid bias is increased by the potential across the resistor |32, delivered to the grid |2| through the switch |56 and the resistor |55. As will be hereinafter described, the grid voltage of the tube |20 is further controlled by the operation of the tube I 43. It is preferable to connect the switch 56 mechanically with the arm |53 through a common shaft (as indicated by the dotted line |51) so that one portion of the shaft motion. moves the arm of the switch |56 leftward to increase the bias, after which continued shaft motion serves to adjust the arm |53 on the resistor |54.

As previously mentioned, the battery |44 overcomes the slight coupling between the windings 90 and 9| of the synchronizing means when the armature 81 is not disposed between the poles. and no current flows in the plate circuit of the tube |43 at this time.' However, when the armature 81 closely couples the windings 60 and 9|, this overcomes the bias of the battery |44 and plate current flows through the tube |43. This controls the grid potential on the time-base tube |20 to cause firing'thereof. In this connection, the plate current of the tube |43 flows from the conductor |29 through the resistors |30 and |54 to the plate of the tube |43, then to the cathode and through conductor |50 to the resistor |55 whence it can return to the conductor |28 through switch |56. if thrown tothe left. or through the resistor |32 if the switch is thrown to the right. Correspondingly, the current flowing through the `plate circuit oi the tube |43 controls the grid voltage of the tube |20. A synchronizing impulse is thus created when the armature closely couples the windings 90 and 9| as the suddenlyincreased plate current of the tube |43 builds up the grid voltage on the tube |20 and causes it to nre.

In adjusting the time=sweep circuit |0 thus far described, the pump may be set into operation while in an accessible or inaccessible position. With the switch |56 thrown to the right. the frequency oi the discharge of the condenser ||5 may be adjusted by moving the arm |31 as previously described. In the particular system shown, it has been found desirable to make the frequency of discharge of the condenser H5 about the same as the strokes per minute of the pump. The common operative connection between the switch |56 and the arm |53 is then moved so as to first move the switch arm to the left, after which the arm |53 can be adiusted. This motion of the switch |56 increases the grid bias on the tube |20, as previously described, to prevent premature ring of the time-base tube |20 and to permit a variation of about plus or minus in pump speed'from the mean value, while maintaining synchronous operation of the indicating means. In other instances, this change in grid bias may be such as to permit a considerably greater speed deviation without destroying synchronous operation of the indicating means.

Later adjustment of the common operative connectionrbetween the switch |56 and the arm |53 permits adjustment of this arm with respect to the resistor |54. This adjustment can be made to such a degree that the tube will fire each time the armature 81 is at the top of its stroke after a completed pump cycle, or this adjustment .the screenbetween successive firing of can be made to such a degree that the tube |20 will lire only on the completion of alternate cycles or, in fact, upon completion of a predetermined number. of cycles. This is possible because as the charge on the condenser ||5 increases with respect` to time, a`diil`erent grid voltage is required to cause the tube I 20 to lire. If', for example, the rate of build-up of the voltage on the condenser ||5 is quite slow, the grid potential of the tube |20 at the time .the armature 61 first couples the windings 90 and 9| may not be sufficient to fire the tube. However, on the succeeding stroke, the potential of the condenser l5 may have built up suiciently to cause the tube |20 to fire when the armatureclosely couplesthe windings 90 and 9| at the end of the ,second stroke. By appropriate adjustment, the tube |20 can thus be made to lire at the end of each cycle (a situation which will be presumed in the later description), at the end of alternate cycles, or at the end of a predetermined number of cycles. For example, the system can be such that movement of the arm |53 to the right` will cause the tube |20 to fire at the end of each cycle, while movement of the arm |53 to the left will cause the tube to fire once every two cycles.

It will be clear from the above that the synchronizing means comprising the windings 90 and 9| and the armature 81 can be used to fire the time-'base tube |20 in synchronism with the mo-A tion of the pump plunger. However, as soon as the armature starts its downward motion, the voltage on the condenser l I5 will begin to build up as a function of time and will continue to build up until the tube |20 again fires. This time-related potential (corrected, if desired, by the orthoamplifier I2) thus represents a saw-tooth potential which can be applied to the plates |02 and |03 of the cathode ray tube to move the spot horizontally across the screen |06 repeatedly, the spot returning synchronously to the left-hand or starting position when the tube 20flres.

To operatively connect the output of the orthoamplier H2 to the cathode ray tube, a variable resistor |60 is connected between the plate o! the tube |26 and an adjustable arm |6| bearingagainst the resistor |30. Movement of the arm 6| serves to center the spot on the screen |06 or to adjust its vertical position thereon. This arm, after such adjustment, remains set during the test. lThe arm IGI is connected to the vertical deflection plate |04 and the horizontal deilection plate |02 by a conductor |62, which is preferably grounded as shown. The variable res istor |60 includes an arm |63 which is connected to the horizontal deflection plate |03 through a co` ductor |64, a selector switch |65, to be later de cribed in detail, and a conductor |66. Shifting of the arm |63 determines the magnitude of travel of the spot on the screen |06 and thus can vary the abscissa scale of the curve to be traced on the tube It is preferable to use a source of relatively high frequency to energizethe winding 90, as well as the windings 11, 86, and' 6|. The frequency should be suiliciently high to make possible the recor-ding of transient phenomena, and this frequency should be so chosen as to be widely divergent from the frequency of reciprocation of the v pistons. Also, it should be suiflciently high that designed for a frequency of 5000 cycles, the source being generally indicated in Figure 9 by the numeral |10. This source is shown as including an output transformer with conductors lll and |12 connected thereacross. The winding 90 is shown as being connected between the conductor lll and a tap of this secondary winding, in which event the voltage across the primary winding 90 will be a fraction of that used in energizing the other windings. 'I'he impedance of the fractional portion of the output transformer energizing the l winding 90 should preferablyrbe matched in impedance with respect to this winding.

To provide for the selective indication of various dynamic phenomena on the screen |00, I pro- Yvide the selector switch |65, including contacts llt, H (connected to the conductor |56), and llt. together with an arm lll (connected to the conductor |55) capable of selective engagement with these contacts. A companion selector switch |80 includes contacts lul, |32, and |83', with an arm |80. The arms il? and |813 are preferably o n the same shaft and can assume three positions, indicated respectively as positions Nos. 1, 2, and 3. As will be hereinafter explained, when the selector switches are in position No. 1 (the arms l'l'l and |86 respectively engaging the contacts llt and lBl), there will appear on the screen |06 a curve representing the relationship between valve motion and pump pressure or motor pressure. When the selector switches are in their No. 2 position, there will appear in sequence on the screen |05 curves with respect to time, indicating piston motion, valve motion, pump pressure, and motor pressure. When the selector switch is in No. 3 position, there will appear on this screen a curve indicating the relationship between piston travel and pump pressure or motor pressure.

To make provision for the showing of either pump pressure or motor pressure as a coordinate of the curves traced on the screen |06, and to provide for the tracing of successive curves of piston travel, valve travel, pump pressure, and motor pressure, I provide a sequence switch, indicated generally by the numeral at the bottom of Figure 9. This sequence switch is formed of four switch banks, indicated generally by the numerals |9| to |90, each switch bank including four contacts, designated by the suiixes a, b, c, and d as shown. For example, the bank HM includes a contact l94a, shown as extending down- Ward to be engaged by a cam late. When the lobe of the cam presses the contact lgda rightward, it electrically connects this contact with contact |9013. This rightward motion is also transmitted by an insulated connection |95 to the contact lldc, moving this rlghtward until electric contact is made with contact |94d. As soon as the lobe of the cam lime is moved to its position shown, the contacts will separate as illustrated. The construction of the other switch banks ll, |92, and |93. is identical and corresponding cams l9le, |928, and lte operate these banks in an identical manner except that the lobes of these cams are displaced successively 90 from each other. These cams are shown as mounted on a common shaft |95 which, when turned, will close successively the switches of the four banks, beginning with switch bank |9| which, in Figure 9, is shown closed.

The shaft |96 is preferably driven step by step.

For example, I have shown diagrammaticaily a four-toothed ratchet |91 adapted to be turned by a latch |98 providing an armature I 99 at its upper Each time this winding is energized, the latch |08 will be pulled upward to turn the ratchet |97 through 96 and thus close the banks of switches successively. A spring-actuated follower 20| is disposed to engage successive faces of the teeth of the ratchet |91 to prevent any possibility of reverse motion of the shaft |96 as the latch |98 moves downward when the winding 200 is deenergized preparatory to grasping of the next tooth.

One terminal of the winding 200 is connected by a conductor 203 with a source of potential 200, indicated as a commercial frequency, commercial-voltage line. The other side of this line is connected to a cathode 205 of a triode 20S. The other terminal of the winding 20|) is connected by conductor 208 and switch 209 with the plate of the triode 206. The switch 209 is preferably on the same shaft as the arms |11 and |81! in such relation that this switch is closed when the arms are in position No. 2 but open when these arms are in positions Nos. 1 and 3.

The grid and plate of the triode 206 are connected respectively to the switch contacts |22 and |23 of the relay to be short-circuited each time the winding i6 of this relay is energized. It will be clear that this short-circuiting occurs instantaneously during the short interval of ring of the time-base tube |20. Correspondingly, at the end of each piston stroke (if the system is thus adjusted), the condenser ||5 will be discharged through the relay, the contacts of which shortcircuit the grid and plate of the triode to cause it to operate as a two-element rectier so that the alternating potential of the commercial source is rectified and allowed to pass for a short interval of time through the winding 200 to raise the latch |99 and advance the sequence switch |90 to the next position. It will be clear that when there is no potential on the grid of the triode 20B, no current ows from the source 200 through the winding 200, but when the grid and plate are interconnected, rectied current is delivered to this winding of the sequence switch to close successively the contacts of the four banks in step with the reciprocations of the pistons.

In general, it is the purpose of the invention, when selector switches |65 and |80 are in the No.2 position, to connect the time-base circuit ll to the horizontal sweep circuit of the cathode ray tube lill and to apply successive potentials to the vertical sweep circuit of the tube, the first-applied potential varying proportionally with pump pressure, the second-applied potential varying proportionally with motor pressure, the third-applied potential varying proportionally with valve travel, and the fourth-applied potential varying proportionally with piston travel. The sequential connection is obtained by the successive closing of the contacts of switch banks |9I, |92, |93, and |94, respectively. Correspondingly, the screen |06 of the cathode ray tube will show curves on successive strokes, each representing the relationship between these four variables (as ordinates) and time (as abscissa).

With this desideratum in mind, a detailed explanation of the remaining circuits will make clear one operative connection which will be found particularly advantageous.

The mode of connection of the electric pressure gauge will be apparent with reference to the lower pressure gauge shown in Figure 9 and responsive to pump pressure. Here, the primary winding |i| can be connected directly between the conductors and |12 to receive the relatively high-frequency potential, though it is preferable to interpose a. potentiometer 215, or other voltage-varying means, in the circuit as shown to adjust the amplitude of vertical travel of the spot or other indicating means. The windings 59 and 60 are connected together differentially, the common terminal being connected by conductor 216 to the center of an output resistor in the nature of a doublepotentiometer providing arms 2 I 8 and 219 which are interconnected to move as a'unit. The remaining terminals of the windings 59 and 60 are connected to the corresponding ends of the output resistor through two rectifying means, which may be of the dry disc type or of other type. As shown, a vacuum tube means is used in this regard, including a double-element tube '/220, which may be a Duodiode of the 6H6 type,

connected as indicated (filament circuits here, as elsewhere, being omitted for purpose of clarity).

When the armature 53 of the pressure gauge is in a substantially central position, the potentials produced in windings 59 and 60 will be substantially equal and the voltage drops across the re.

spective halves of the output resistor will be equal so that no current flows through the conductor 21-6. If, however, the armature is displaced in one direction, the potential across the winding 60 will increase and across the winding 59 will decrease, and the voltage drops across the halves of the output resistor will not be equal, thus changing the potential relationship between the arms 218 and 219 in proportion to the pressure change resulting in this displacement of the armature.

The arm 218 is connected by a conductor 221 to the blade 191d, and if the switch bank 191 is closed, current will flow to the blade 191C (connected common to the blade 192e), and thence through a conductor 222 to the grid or input circuit of an amplifier 225, which may be of conventional construction, as diagrammatically indicated in Figure 9 which shows a single stage of amplification, using a tube of the 6J? type, for example, indicated by the numeral 226. The remaining terminal of the input circuit of this amplifier is connected by a conductor 221 to the arm 219. After being amplified, the current passes from the plate of this tube through a conductor 228 to the blade 191b (connected in common with the blade 192b). If the switch bank 191 is closed, this current flows throughythe blade Isla. and through a conductor 229 (connected common to all of the blades 191a, 19211, 193er, vand 19M) to the vertical-displacement plate 105 of the cathode ray tube. The other vertical-displacement plate 104 is connected through the conductor 162 to the other output terminal of the amplifier 225.

Correspondingly, if the switch bank 191 of the sequence switch 190 is closed, modifications of Ipump pressure will be changed into corresponding electric changes and delivered through the switch bank 191 to the vertical sweep circuit of the cathode ray tube to cause movement of the electronic beam vertically in proportion to the change in pressure. If, at the same time, this beam is moved horizontally in response to time, the beam or spot will sweep out a curve showing the relationship of pump pressure to time.

It is desirable to be able to adjust the vertical position of the spot formed by impingement of the electronic beam on the screen 106, thus changing, in effect, the base line of the curve swept out. This may be accomplished by the simultaneous movement of the arms 218 and 219.

The mode of connection of the other pressure gauge responsive to motor pressure is similar and need not be explained in detail, being shown in Figure 9 with primed numbers. Suice it to say that the arm 218 is connected by a conductor 231 to the blade 192d, while the arm 219' is connected to conductor 221. Correspondingly, if the switch bank |92 of the sequence switch 190 is closed, the pressure-dependent potentials between the arms 218 and 219' will be delivered through the switch bank 192 to the input of the amplifier 225, the

output thereof being connected through the switch bank 132 to the vertical-displacement plates and 104, as previously indicated. Correspondingly, when the switch bank 192 is closed, the electronic beam will be deflected vertically in proportion to the pressure variations in the motor cylinder and a curve, giving the relationship between this pressure and time, will be swept out on the screen 106.

Referring now to the circuit responsive to valve travel, the winding 11 is shown as connected in series with a variable impedance 235 to receive the potential of the source 110. Preferably, this potential is made variable by a T-pad resistor 236, or other variable resistance means, a T-pad resistor being preferable as it will maintain substantially constant input and output impedance, regardless of the setting thereof, this device serving to control the amplitude of the valve-travel trace. The variable impedance 235 may be a variable inductance or, as shown, a variable resistor, the arm thereof being connected to one end of the resistance. Correspondingly, the voltage derived from the source is divided between the winding 11 and the impedance 236, the impedance of the latter being of the same order as that of the winding 11 so that the current and voltage in the two portions of the output circuit (to which the winding 11 and the impedance 235 are respectively connected, as will be described) will have substantially the same potential rela-- tionship. In some instances, I prefer to inductively energize the winding 11, as by winding a primary winding on the poles 16, the winding 11 then being the secondary winding and being connected as shown in Figure 9.

The output circuit connected to the winding 11 and the variable impedance 235 preferably includes two rectiiiers associated with the respective halves of the circuit, and indicated generally by the numerals 231 and 230. These rectiiiers may be of any suitable type, for example-copper oxide rectiiiers can be used, or rectiflcation can be obtained by use of vacuum tubes. The rectiflers can be directly across the respective halves of the circuit, in which event it is best to have the impedances of each half match that of its corresponding rectifier. However, I prefer to interpose transformers 240 and 241 therebetween, the secondary windings of these transformers respectively matching the impedances of the rectiiiers 231 and 238. The primary windings are connected as shown, respectively across the variable impedance 235 and the winding 11. It is usually desirable that the transformers 240 and 24| provide cores of magnetic material and, in this event. these cores should be separate rather than common to the two transformers.

The common terminal of the secondary windings of these transformers is connected by a conductor 242 to a center tap of an output resistor 243, the end terminals of which are connected to the rectiers. Vacuum tube rectification is diagrammatically shown in Figure 9 as, for example, by use of a tube of the 6H6 type providing dual rectification, the output being fed to the ter- 2,897,032 v minals of the output resistor 243. .The upper terminal of this resistor is shown as connected to a conductor 244 extending to the contact |8| of the selector switch |80 and to the blade |93d of the switch bank |93. If the switch bank |93 is closed,

e current can 4then ow to the blade |93c (connecttric changes corresponding to valve travel, and

which appear acrossthe output resistor 243, will VVbe delivered to the input of the amplifier 250.

One of the output terminals of this amplifier is connected by a conductor 252 to the conductor |32, and the other output terminal is connected by a conductor 253 providing branches leading to the contacts |10 and |15 of the selector switch |35 and to the blade |9317 (connected common to the blade G9022). If the switch bank |93 is closed, this output current flows from the blade |93b through the blade |93a, and through the conductor 229 to the*vertical-displacement plate |05 of the cathode ray tube. Correspondingly, if the time sweep circuit ||0 is in operation and the switch bank |93 is closed, there will be produced on the screen |06 a trace representing valve travel (as ordinates) and time (as abscissa).

It is preferred to use an ortho-amplier 250 to compensate for any non-linearity or non-proportionality of the input voltage with respect to movement of the tapered sleeve 12, representing valve motion. In some instances, the potential across the output resistor 203 will not vary exactly proportionally with piston displacement, yet it is usually desirable to deliver to the cathode ray tube a potential which varies substantially linearly or proportionally with the movement of the tapered sleeve l2 unless the resulting trace or curve on the screen l00 is interpreted with this in mind. While linear or proportional potentials can be produced l-across the output resistor 243 by changing the design of the taper of the sleeve l2, nd it preferable to make what compensations are desired by use vof the ortho-ampliiier 250.

This can be done by using an ortho-amplifier having a characteristic curve which eiects the compensation for the non-linear or non-proportional potentials reected across the output resistor 203. This correction can be explained generally by reference to Figure 8 if the straight line l i0 is considered as representing the desired linearly-varying potential to be applied to the vertical sweep circuit of the cathode ray tube. The curve with different coordinates may be considered as representative of the non-linear input to the ampliiler, though it should be understood that the showing is exaggerated to some extent and is made without attempt to plot actua1 values. If the characteristic curve of the amplifier is represented in part by the curve ||3 (also with different coordinates), the output will be substantially linear, as suggested by the straight line output of the amplier, it is possible to do this over a more limited range of amplifier operation, but sufficient to take care of the full operative range of the indicating means to give the desired compensation.

In adjusting preliminarily the electric system responsive to valve travel, the following procedure can be used. With no input from the source |10, the spot may be adjusted to coincide with a selected base line on the screen |06 'by adjustment of the tapped-off potential applied to the vertical-displacement plate |04 through the conductor 252 by moving an arm 255. The input can then be connected and the amplifier appropriately adjusted until the spot moves vertically in direct proportion with movement of the valve. This proportionality can be checked by displacing the valve diierent amounts and measuring the displacement of the spot from the selected base line. The valve can then befmoved to its central or mean position while the pump is accessible for measurement of valve position. The variable irnpedance 235 is then adjusted to bring the spot to coincide with the selected base line, if it; is not already there, and subsequent variations in p0- tential from the source |10 will not shift the spot from this base line (though they may change the amplitude of motion of the spot, thus making it desirable to use a constant-voltage source). In general, the desired amplitude of vertical motion of the spot is obtained by adjusting the Tpad 236, as previously described. Thus adjusted, the pump can be installed in an inaccessible position and the spot will move vertically with respect to the screen |03 in a manner which is proportional to valve travel.

Regarding the circuit for indicating piston travel, the general elements of the circuit are the same as just described with reference to the valve travel circuit, and primed numerals have been employed to indicate the relationship. Suffice it to say that one terminal ofthe corresponding output resistor 243' is connected by a conductor 258 to the contact |83 of the selector switch |80 and to the blade |94d of the switch bank |94. If this bank is closed, current can flow to the blade |9c and thence through the conductor 245 to the input of the ampliiier 250, as previously described. The remaining terminal of the output resistor 203 is connected to the conductor 25| by a conductor 259 so as to be common to the corresponding terminal of the output resistor 203.

Correspondingly, if the switch bank |94 is closed and the time sweep circuit ||0 is in operation, electric changes corresponding to piston travel will be applied across the input of the amplifier 250. The output of the amplifier will be fed through conductor 253, blades |94b and |9lia, and conductor 229 to the vertical-displacement plate |05. At this time, the spot will trace on the screen |06 a curveof piston travel (as ordinates) and time (as abscissa).

It will be clear that the circuits responsive to pressure variations and valve and piston travel are diagrammatically shown, and that various changes can be made therein without departing from the spirit of the invention. Various alternatives to these circuits are disclosed in my applications supra, which contain also a more detailed explanation of the operation and the method of adjustments of similar circuits.

It will be apparent from the foregoing that, if the selector switches and |65 are in their No. 2 position (at which the time switch 209 is closed), the time sweep circuit will move the spot horizontally across the screen |06 successivelyl the start of each horizontal displacement being exactly in synchronism with the start of a piston cycle; During the first horizontal sweep, vertical displacements oi the spot will be in proportion to pump pressure, the switch bank |9| being closed. During the second horizontal sweep, all of the switch banks will be open except the bank |92, and vertical displacements will be in proportion to motor pressure. During the third horizontal sweep, all of the switch banks will be open except the bank |93, and vertical displacements will be in proportion to valve travel. During the fourth horizontal sweep (completing the cycle), all of the switch banks will be open except the bank |96, and vertical displacements will be in proportion to piston travel. The successive curves traced onW the screen 58S can be photographed, directly or indirectly, or if visual observation alone is desired, a screen |06 of the re-s tent-.ive type can be Vused to make the curves persist until re-tracecl by the spot. Correspondingly, four superimposed curves can be obtained on the screen |06, each with the same base line and, from these curves, operating conditions in the pump can be accurately ascertained.

If the selector switches 80 and 55 are moved to their No. 1 positions, this will open the switch 209 to render inoperative the sequence switch |90. However, the sequence switch can be stopped with any one of the switch banks closed, or it can be manually turned to close the switches of any particular bank. By throwing selector switches |00 and it to their No. l position, it is possible to obtain a trace on the screen |06 of the valve motion. (as abscissa) and either pump pressure or motor pressure (as ordinates), depending upon whether switch bank itl or |92 is closed. Assuming that a curve of valve motion with respect to motor pressure is desired, the switch bank |92 will be closed and the circuits can be traced as follows.

The output from the valve-travel output-resistor 253 is delivered to the input of the amplifier 250, one side of the circuit being through the conductor and the other side of the circuit being through conductor 244, contact |0| of the selector switch |00, and arm |84 to the grid circuit of the amplifier 250. The output potential from the amplifier will be delivered on one side through conductors 252 and I 62 to the horizontalpoint on the resulting curve will show the instantaneous relationship between valve travel and motor pressure.

Iiselector switches |80 and |65 are moved to their No. 3 position, the switch 209 will likewise be open to render inoperative the sequential operation of the sequence switch |90. At this time, a curve can be obtained on the screen |06 showing the relationship between piston travel (as abscissa) and pump pressure or motor pressure (as ordinates), depending upon whether the switch bank |9| or |92 is closed. Assuming that the relationship between piston travel and pump pressure is desired, the operator will close the switch bank |9| and the circuits can be traced as follows. The output produced by piston dis- Y placements will be transmitted to the amplifier 250, one half of the circuit including conductors 258 and 25| and the other half of the circuit including conductorV 258, contact |83, arm |84, and that portion of the conductor 245 which extends to the grid circuit. The output of this amplifier will be delivered on one side through conductors 252 and |62 to the horizontal-displacement plate |02, and on the other side through conductors 253, contact |16, arm |11, and conductor |66 to the horizontal-displacement plate |03.

The electric variations corresponding to pump pressure will be delivered, on one side, through conductor 227 to the amplier 225 and, on the other side, through conductor 22|, blades |9Id and |9|c, and conductor 222 to the grid circuit of the amplifier. The output of the amplifier is deliveredy on one side, directly to the conductor |52 and thence to the vertical-displacement plate |04 and, on the other side, throughthe conductor 228, blades |9|b and |9la, and conductor 229 to the vertical-displacement plate |05.

It will be clear that the invention is applicable to the recording of various dynamic phenomena, the present showing being exemplary of its Versatility. By use of the system, Various phenomena can be indicated individually or successively Vwith respect to time or with respect to other variables,

and the relationship between one dynamic phedeilection plate |02. On the other side, this outy put is deliveredthrough conductor 253, contact |14, arm ill, and conductor |66 to the horizontaldeflection plate |03. As switch banks |93 and |94 are opened, neither the input not output currents flow therethrough. 'I'his will cause horizontal displacement of the spot (as distinct from the vertical displacement described with reference to the sequential operation) to move the spot horizontally in proportion to valve travel.

The output from the circuit responsive to motor pressure is delivered, on one side, directly to the input of the amplifier 225 through the conductor 221. On the other side, this output is delivered through the conductor 23|, blades |92d and |92c, 65

and conductor 222 to the grid circuit of the amplifier 225. One leg of the output circuit of this amplifier is connected to the vertical-displacement plate |04 through the conductor |62. The

nomenon and another can be shown either instantaneously or as a curve. Furthermore, the system provides for a mode of connection in which electric changes corresponding to a given dynamic phenomenon can be applied to the indicating means, such as the beam of a cathode ray tube, so as to deflect this selectively in either a horizontal or a vertical direction. This is exemplified, for example, by valve travel which 5 can be shown as abscissa (when the selector invention which, for the purpose of ready understanding, has been simplified in the foregoing description and in the appended drawings, but which has been described in sufficient detail to make apparent to those skilled in the art the mode of operation and other uses and modications.

I claim as my invention:

l. In a device for indicating or analyzing changes in a dynamic phenomenon, the combiother leg of the output circuit conducts current nation of an electric indicating means providing through the conductor 228, the blades |9211 and |92a, and the conductor 229 to the remaining vertical-displacement plate |05. Corresponding- 1y. the spot will move vertically in response to changes in motor pressure, and the position of a movable means movable in a given direction and iat right angles withy respect to said given direction; operating means for delivering to said indicating means electric variations corresponding to said changes in said dynamic phenomenon; switch asoma:

means associated with said operating means for selectively .delivering said electric variations to said indicating means to move said movable means selectively in said given direction and at right angles with respect thereto; and means for delivering to said electric indicating means simultaneously with such delivery of electric variations thereto another electric variation to move said movable 'means in a direction at right angles to the direction in which said rst-named electric variations tend to move said movable means whereby. for example, said movable means can trace successive curves in which the ordinates and abscissa are selectively used for indicating said changes.

2. In a device for indicating or measuring two cyclically-occurring phenomena, the combination of: a rst means for translating one of said phenomena into a corresponding electric variation; a second means for translating the other of said phenomena into a corresponding electric variation; electronic means providing an electronic beam directed toward a receptive surface and including a pair of circuits adapted upon respective energization to deflect said beam in directions at right angles to each other; sweep means con nected to one ci said circuits for repeatedly sweeping said electronic beam .across said receptive surface in one of said directions; a sequence switch means for alternately applying said electric variations to the other of said circuits to deflect successive sweeps of said beam in the other of said directions to produce traces representing 'said two cyclically-occurring phenomena as one and the same coordinate; and a selector switch means for disconnecting said sweep means from said one of said circuits and connecting said rst means thereto to sweep said beam in said one direction in response to changes in said first phenomena while retaining the application to said other of said circuits of said electric variation corresponding to said second phenomena to sweep out a curve, each coordinate of which represents one of said phenomena to indicate variations in one of said phenomena with respect to the other.

3. In a device for indicating or measuring a plurality of cyclically-occurring -phenomena in a reciprocating mechanism, the combination of: a rst means for translatingl one of said phenomena into a corresponding electric variation;

a second means for translating another of said phenomena into a corresponding electric variation; electronic means providing an electronic beam directed toward a receptive surface and including a pair of circuits adapted respectively to deect said electronic beam in directions at right angles to each other; means connected to one of said circuits for repeatedly moving said electronic beam across said receptive surface in one of said directions at a frequency independent of the frequency of reciprocation of said mechanism, said means providing an adjustable means for adjusting the frequency of such movement of said electronic beam to a frequency near the frequency of reciprocation of said mechanism irrespective of input from said first or second means; synchronizing means for starting each of said movements of said beam when said reciprocating mechanism assumes a predetermined position in its cycle; and switch means for sequentially connecting said rst and second means to the other of said circuits to apply said electric variations thereto in a manner to deect said beam under the influence of both said circuits to sweep out successive curves in the same general area of said receptive surface.

4. A combination as dened in claim 3. in which said synchronizing means includes a movable armature reciprocating with said mechanism, a magnetic circuit providing a space to receive said movable armature, and means responsive to a change in reluctance of said magnetic circuit when said armature changes its position with respect to said space for starting each of said movements of said beam in said one direction, said last means including a control winding coupled with said magnetic circuit.

5. In a device for indicating or measuring a plurality of cyclically-occurring phenomena in a reciprocating mechanism, the combination of: a

first means for translating one of said phenomena into a corresponding electric variation; a second means for translating another of said phenomena into a corresponding electric variation; electronic means providing an electronic beam Adi rected toward a receptive surface and including a pair of circuits adapted respectively to deilect said electronic beam in directions at right angles to each other; electromagnetic means for creating electric impulses in timed relationship with the reciprocations of said mechanism, said means including a movable armature reciprocating with said mechanism and means providing a magnetic circuit and an armature-receptive space therein and means including a winding linked with said magnetic circuit whereby the reluctance of said i winding changes suddenly when said armature enters and leaves said space to-establish said electric impulses; means triggered by said impulses and connected to one of said circuits to deect said electronic beam to move across said receptive surface; a sequence switch adapted when in one position to connect said first means to the other of said circuits and when in another position to connect said second means to said other of said circuits; a step-by-step operating means for moving said sequence switch from one position to the other; and means for moving said operating means step by step in response to said electric impulses.

6. In a device for indicating a cyclically-occurring phenomenon in a reciprocating mechanism, the combination of: means for translating said phenomenon into a corresponding electric variation; electronic means providing a receptive surface and an electronic beam directed toward said receptive surface, said electronic means including a `pair of circuits adapted respectively to deflect said electronic beam.. along coordinate axes; means for impressing said electric variation on one of said circuits to deiiect said electronic beam in a direction along one of said coordinate axes in response to said cyclically-occurring phenomenon; a condenser; means for progressively increasing the potential across said condenser with the passage of time; means for impressing on the other of said circuits a potential substantially proportional to the potential across said condenser to deect said electronic beam in a direction paralle] with the other of said coordinate axes; a time-base electronic tube providing tube elements comprising a biased grid; circuit means for connecting said tube elements to said condenser to apply the increasing condenser voltage to said tube elements in such manner that the tube will re to discharge said condenser when such applied voltage overcomes the bias of said grid; an electronic control tube providing a control grid. an anode, and a cathode; a grid circuit connecting said control grid and said cathode; electric synchronizing means in Said grid circuit for changing the potential on said control grid each time said reciprocating mechanism assumes a given position in its cycle of motion, thereby changing the potential of said anode; and means for connecting said anode to said biased grid of said time-base tube to change the potential of said biased grid of said time-base tube to discharge said condenser when said reciprocating mechanism i-s in said given position 5 in its cycle of operation.

RICARDO MESTAS. 

